Among cases where stapling a stack of paper, a stapler has often driven the staple into the stack of paper to staple the stack of paper until now. This stapler contains a clincher arm, a magazine, a pusher, a driver arm, a driver, a handle, and the like. The pusher pushes a strip of staples loaded in the magazine to bias it onto a staple-pushing-out slot of the magazine.
When any clinching force is applied to the clincher arm, the magazine, and the driver arm, which share a main shaft with their shaft-receiving portions, through the handle, the driver provided at a forward end of the driver arm drives a top staple of the strip of staples loaded in the magazine out of the staple-pushing-out slot. For example, a forward end of the driver is formed flat and pushes the whole crown portion of the staple to drive it out. Since the driven staple comes into contact with a clincher provided with a forward end of the clincher arm, the legs thereof are clinched round or flat.
When this operation is performed with the stack of paper being clipped by the magazine and the clincher, the staple, the legs of which are clinched round or flat, can staple this stack of paper.
In relation to such a conventional example, Japanese Patent Application Publication No. H09-085644 has disclosed a stapler on page 3 and FIG. 2 thereof in which a forward end of pushing-out portion for pushing the staple out is formed so as to be concave. According to this stapler, both ends of the concave forward end of the pushing-out portion contact portions of the staple over the legs thereof when pushing the staple out. This enables any force applied to the staple by the pushing-out portion to be concentrated on the legs of the staple so that it can be more increased than that of a past case.